저온 졸젤 공정 ZnO 박막을 적용한 정구조 고분자 태양전지 연구

Abstract

The performance of conventional polymer solar cells with low-temperature-processed zinc oxide (ZnO) as an electron extraction layer is investigated in this study. Conventional polymer solar cells consist of molybdenum oxide (MoO3) as a hole extraction layer, a poly (3-hexylthiopene): phenyl-C60-butyric acid methyl ester (P3HT:PCBM) bulk heterojunction as a photo-active layer, and ZnO as an electron extraction layer. The ZnO layer is formed from a precursor solution on the P3HT:PCBM film through sol–gel spin-coating and annealed at a low temperature (~150°C). We first investigated various solvents of the ZnO precursor solution to identify the best solvent for coating the ZnO layer on the P3HT:PCBM film. Using the best ZnO precursor solution, we fabricated polymer solar cells under various ZnO thicknesses and analyzed their photovoltaic performance to obtain the optimal thickness of the ZnO layer. The device with the optimal thickness of the ZnO film showed a ~10% higher short-circuit current density and power conversion efficiency than the devices without the ZnO film.